The invention relates to a trailer hitch for an agricultural or industrial work vehicle.
For conventional trailer hitches, several coupling systems, such as set forth in the standards ISO 6489 1-5, can be installed on the same carrier body only with restrictions. By exceeding the installation space, the position or the function, compared to an individual add on structure, is not completely usable. When changing from one trailer system to the other or when changing components due to wear and tear, very often the entire trailer block must be exchanged with the coupler or towing member. To enable multi purpose use of an agricultural or industrial work vehicle, especially a tractor, equipped with a trailer hitch, it is desirable to provide several coupling options for the trailer system.
A height adjustable trailer coupling is described in EP A 0 155 338 which shows a coupling jaw mounted on a coupling jaw carrier. The coupling jaw carrier is supported on its side by a trailer block, which is mounted on the vehicle by means of screws. The trailer block includes two side plates, each of which carries, on its end facing away from the vehicle, a guide rail with vertical guide grooves in which the coupling jaw carrier can move in the vertical direction. Threaded rods and nuts help to realize side stabilization of the trailer block and simultaneously set the distance between the two guide rails. The guide rails have vertical holes spaced apart from each other. The coupling jaw carrier has locks that can engage selectively in these holes, thus locking the coupling jaw carrier at a corresponding selected height position. It is desirable to provide towing members in addition to the height adjustable coupling jaw. The arrangement of additional towing members, however, is made considerably more difficult or impossible by the coupling jaw carrier, due to spatial limitations.